Pediatric Examination and Board Review (103 page)

A mother brings her 7-month-old full-term twins in to see you for a routine check-up. During the visit she mentions that she is concerned because they both seem to have “crossed eyes” a lot of the time, especially when they are tired or at nighttime.

On examination, of the first child you note that her eyes appear asymmetric. Her left eye appears to deviate inward. She has an asymmetric corneal light reflex, with the left corneal light reflection displaced temporally.

SELECT THE ONE BEST ANSWER

1.
All of the following cranial nerves are involved in alignment of the eyes except

(A) II

(B) III

(C) IV

(D) VI

(E) no exception; all of the above are involved

2.
Which type of strabismus does she have?

(A) esotropia

(B) esophoria

(C) exotropia

(D) exophoria

(E) pseudostrabismus

3.
What is the most appropriate next step for this patient?

(A) observation with reexamination in 3 months

(B) ophthalmology referral

(C) Snellen visual acuity test

(D) cover test

(E) eye patch

4.
If you send her to the ophthalmologist, who confirms your diagnosis, what is the
most
likely treatment of this disorder?

(A) surgical correction

(B) eyeglasses

(C) eye patch

(D) observation

(E) prism glasses

5.
What percentage of untreated children with strabismus develop amblyopia?

(A) 10-30%

(B) 20-40%

(C) 30-50%

(D) 50-80%

(E) 90-95%

6.
You examine her twin sister and note that her eyes also appear asymmetric. Her right eye appears deviated inward throughout the examination. Her corneal light reflex is normal. Which type of strabismus does she have?

(A) esotropia

(B) esophoria

(C) exotropia

(D) exophoria

(E) pseudostrabismus

7.
What is the next recommended action for the patient in question 6?

(A) reassurance

(B) ophthalmology referral

(C) prescription for glasses

(D) eye patch

(E) surgical correction

8.
A father brings his 3-year-old son to your office one day because of a “lazy eye” they have been noticing for a few months. His father does not recall any trauma to the eye and tells you that both he and the patient’s mother wear glasses. His son rides a tricycle, helps dress himself, can copy a circle, and uses 3-word sentences. The “lazy eye” doesn’t seem to bother him. On examination, you note a left esotropia, an asymmetric corneal light reflex, and an abnormal cover test. What will the treatment be for his
most
likely diagnosis?

(A) eye patch

(B) prism glasses

(C) prescription eye glasses

(D) surgical correction

(E) observation

9.
Which of the following children does
not
require a referral to a pediatric ophthalmologist?

(A) a 6-month-old with fetal alcohol syndrome

(B) a 2-week-old with nystagmus

(C) a 5-year-old with Down syndrome

(D) a 4-month-old with intermittent strabismus

(E) a former 26-week premature infant now 9 months old

10.
You see a 3-day-old for a well-baby visit in your office and her mother asks you what she is able to see. What can you tell her mother that her vision would be, approximately, if she were able to read off a Snellen chart?

(A) 400/20

(B) 200/20

(C) 20/20

(D) 20/200

(E) 20/400

11.
Which of the following children needs to be evaluated further for their vision?

(A) a 6-week-old who cannot smile

(B) a 1-month-old who does not fixate and follow parents’ faces across midline

(C) a 5-month-old with intermittently “crossed eyes”

(D) a 15-month-old who cannot put a peg into a round hole

(E) a 2-year-old with mild hyperopia

Questions 12 through 15.
Match
the following ages with the
most
appropriate vision tests and screening tools:

12.
6 months          (A) Allen cards

13.
2.5 years          (B) HOTV or tumbling E’s

14.
4 years             (C) Fix and follow

15.
7 years             (D) Snellen charts

16.
An 8-year-old girl is in your office for a routine checkup. On your questioning, she tells you that she has some difficulty seeing the blackboard in class. Her mother states that she does seem to be holding her books closer to her face lately. Sometimes she squints when they are in the car. What will you most likely find on your fundoscopic examination?

(A) +1.00

(B) +4.00

(C) −1.00

(D) −4.00

FIGURE 63-1.
Ocular muscles. The oculomotor, trochlear, and abducens nerves; and then cranial nerves (II) innervation. (Reproduced, with permission, from Waxman SG. Clinical Neuroanatomy, 26th ed. New York: McGraw-Hill; 2010: Fig. 8-4.)

17.
Which of the following statements regarding myopia is
false
?

(A) most infants’ eyes are slightly myopic

(B) it requires a concave lens to correct

(C) it is often hereditary

(D) most myopia is physiologic

(E) myopia is more common in preterm compared with full-term infants

18.
At what age should children begin to have routine screening visual acuity examinations?

(A) 6 months

(B) 1 year

(C) 2 years

(D) 3 years

(E) 4 years

ANSWERS

1.
(A)
Cranial nerve (CN) III (oculomotor) is responsible for levator muscle constriction, pupillary constriction, and lens accommodation. CN IV (trochlear) innervates the superior oblique muscle and CN VI (abducens) innervates the lateral rectus muscle. CN II (optic) is not involved in aligning the eyes, only in the transmission of visual signals (see
Figure 63-1
).

2.
(A)
This is esotropia because her eye is deviated medially (eso-) and is constant (-tropia) as opposed to periodic or latent (-phoria). The corneal light reflex test is performed by the examiner shining a light onto both corneas simultaneously and watching where on the cornea the reflection occurs. In eyes that are aligned, the reflection appears symmetric. If one eye is deviated, the normal eye is centered and the reflex in the deviated eye appears offcenter. Infantile, or congenital esotropia is the most common esodeviation in children (see
Figure 63-2
).

3.
(B)
Referrals to ophthalmology for strabismus are not generally made before 6 months of age because intermittent asymmetry of pursuit can be present in healthy infants and resolves by 3-6 months (see
Figure 63-3
). Observation is not acceptable because delay in treatment increases the likelihood of amblyopia. The Snellen charts are visual acuity tests for vision screening for older children. The cover test is best used to detect visual axis deviations. Each eye is covered in turn while the uncovered eye is examined for tropias. It is an appropriate test to perform when trying to confirm the presence of strabismus as suspected by abnormal corneal light reflex, but it requires patient cooperation to perform and would likely be difficult in an infant this age.

FIGURE 63-2.
Accommodative esotropia.
A.
Without glasses, esotropic;
B.
with glasses, well-aligned at distance;
C.
and wellaligned at near with bifocal correction. (Reproduced, with permission, from Hay Jr WW, Levin MJ, Sondheimer JM, et al. Current Diagnosis & Treatment: Pediatrics, 19th ed. New York: McGraw-Hill; 2009: Fig. 15-26A-C.)

4.
(A)
It is widely agreed that surgical correction, namely medial rectus recession, is the treatment most likely to be corrective. The timing of the surgery is controversial, some arguing for as early as 3-4 months, some as late as 1 year.

5.
(C)
The amblyopia that commonly accompanies strabismus requires separate treatment.

6.
(E)
This is pseudostrabismus, when one or both eyes appear deviated medially because of prominent epicanthal folds or an especially broad nasal bridge. The corneal light reflex is normal because the eyes are actually aligned and can be confirmed by a cover test in older children.